Copper Bottomed Guarantee

Copper Bottomed Guarantee : Phrases

Meaning:

A guarantee that is Cast Iron in quality.

Example:

The Liberal government issued an election copper bottomed guarantee to clean up corruption, except for Svend Robinson.

Origin:

Wooden ships are particularly prone to damage from underwater rocks and other obstacles; they are also particularly prone to encrustation from barnacles and other sea creatures. In order to significantly reduce the chance of damage, and encrustation, really well built expensive ships were given a copper bottom. This almost guaranteed that they would suffer only minimal damage or encrusting. The smooth bottom meant that they were faster than their rivals and could be guaranteed to arrive earlier.